Microscopy system and method

ABSTRACT

A microscopy system comprises a microscopy optics and a stand supporting the microscopy optics. The stand has a plurality of hinges, of which a first group comprises a position detecting sensor for sensing a hinge position and a second group comprising an actuator for the change of the hinge position. In an automatic control mode, the actuators are controlled in dependence of signals of the position detecting sensors.

This application is a divisional application of U.S. application Ser.No. 10/991,756, filed Nov. 18, 2004 now U.S. Pat. No. 7,110,173, whichclaims priority and benefit from German patent application Ser. No. 10353 961.1, filed Nov. 19, 2003, the entire teachings of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a microscopy system and in particular to asurgical microscopy system comprising a microscopy optics and a standfor carrying the microscopy optics. The invention further relates to amethod of controlling a microscopy system.

2. Brief Description of the Related Art

A microscopy optics generally comprises an objective lens having anoptical axis and an object plane in which an object to be observed is tobe disposed. The microscopy optics is configured to image a region ofthe object being located in a focus region of the microscopy optics.

A stand of a conventional microscopy system comprises a plurality ofstand members comprising a base stand member and an objective lenssupporting stand member supporting the objective lens. Pairs of standmembers are connected to each other by respective such that the hingesof each pair may be displaced relative to each other. For example, thehinge members of the pair may be tilted or swiveled relative to eachother. By operating the hinges, i.e. by displacing relative to eachother the stand members which are connected with each other by thehinges, it is possible, on the one hand, to displace the focus region ofthe microscopy optics towards a desired region of the object ofinterest, and, on the other hand, to orientate an optical axis of theobjective lens such that the desired region of the object is imaged bythe microscopy optics from a desired point of view or under a desiredviewing angle.

The stand of a conventional microscopy system may comprise a group ofhinges allowing a user, in at least one operation mode, to substantiallyfreely displace relative to each other the stand members connected toeach other by the hinges of that group by applying a force to acomponent of the microscopy system. The force may be applied to acomponent such as a stand member or the microscopy optics or any othercomponent provided on the microscopy optics, such as a handle bar orother. The stand members are substantially freely displaceable relativeto each other in that sense that only a low force to overcome such as aremaining frictional force of the respective hinges has to be applied toachieve the desired displacement of the microscopy optics.

To this end, the members of the stand may be balanced such that agravitational force applied to the stand members and the microscopyoptics will substantially not provoke any displacement of the microscopyoptics.

The hinges which are substantially free displaceable in this operationmode may be further provided with a brake in order to block anaccidental displacement of the microscopy optics in another mode ofoperation.

The conventional microscopy system may further comprise another group ofhinges including an actuator to change the relative positions of thestand members which are connected with each other by the respectivehinge of this group. These actuators may be controlled by the user by,for example, a switch or the like. Controlling the actuators may result,for example, in a change of the orientation of the optical axis of theobjective lens.

If the user wants to observe a region of the object being observed froma different point of view or under a different viewing angle, he willgrasp the stand or a component of the microscopy optics with his hand inorder to displace the objective lens to a desired new position. Due tothe displacement of the objective lens, the focus region of themicroscopy optics and the region of interest of the object will nolonger coincide, and the user finally has to reorientate and, ifnecessary, also to displace the optical axis of the objective lens bycontrolling the respective actuators such that the region of interest ofthe object again coincides with the focus region of the microscopyoptics. This procedure is cumbersome and results in that the user, evenif the observation of the object under a different perspective appearsdesirable, either does not perform such observation or requires a longtime for performing the necessary steps.

SUMMARY OF THE INVENTION

In view of the above, it is an object of the present invention toprovide a microscopy system and a method for the controlling amicroscopy system having improved possibilities of changing a desiredpoint of view or viewing angle.

In order to achieve the above object, the invention provides amicroscopy system and method in which some pairs of hinged stand membersare substantially free displaceable relative to each other and someother pairs of hinged stand members are displaceable relative to eachother under control of an actuator associated with the respective hinge,wherein the actuator is controlled based on a position signal of aposition detection system of the microscopy system.

According to an embodiment of the invention, a microscopy system fordisplaying an image of an object to be examined comprises: a microscopyoptics for imaging the object, the microscopy optics comprising at leastone objective lens having an optical axis, an object plane and a focusregion in which the object to be imaged is to be disposed, wherein theoptical axis intersects with the object plane within the focus region;and a stand comprising a plurality of stand members, a first hinge grouphaving at least one first hinge and a second hinge group having at leastone second hinge, each hinge of the first and second hinge groupsconnecting a pair of stand members such that the stand members connectedby the respective hinge may be displaced relative to each other, theplurality of stand members comprising a base stand member and anobjective lens supporting stand member supporting the at least oneobjective lens; the at least one first hinge of the first hinge groupallowing, in at least a first mode of operation of the microscopysystem, a user to freely displace relative to each other the two standmembers hinged together by the first hinge by applying a force to thestand; the at least one second hinge of the second hinge groupcomprising a first actuator for displacing relative to each other thetwo stand members hinged together by the second hinge; the systemfurther comprising: a position detecting system having at least onesensor, wherein the position detecting system is configured to generatea position signal representing a change of a position of the at leastone objective lens based on a sensor signal of the at least one sensor;and a controller, configured to actuate, in the first mode of operationof the microscopy system, the first actuator of the at least one secondhinge to displace the pair of stand members connected by the at leastone second hinge based upon the position signal generated by theposition detecting system.

According to an embodiment of the invention, the position detectionsystem comprises position sensors attached to hinges of a first group ofthose hinges, which are substantially free displaceable for thedisplacement of the objective lens.

According to an embodiment of the invention, the microscopy systemcomprises a controller in order to control an actuator of a hinge of asecond hinge group of hinges based upon the position signal.

According to an exemplary embodiment, the control of the actuator iscarried out such that a displacement of the focus region of themicroscopy optics in the coordinate system is less than a displacementbeing affected by applying of a force to the stand or parts of themicroscopy optics. Thus, the displacement of the focus region in thecoordinate system may be less than 30% of the displacement of theobjective lens in the coordinate system. According to other exemplaryembodiments, the displacement of the focus region in the coordinatesystem may be less than 20%, less than 10% or even less than 5% of thedisplacement of the objective lens in the coordinate system.

Herewith, a required effort to again let the focus region of themicroscopy optics coincide with the interesting region of the objectafter a displacement of the microscopy optics can be considerablyreduced. Preferably, it is possible that the focus region of themicroscopy optics remains at a same position in the coordinate systemeven after displacement of the latter. Changes of the point of view orviewing angle for observation are relatively easy to be obtained,accordingly.

According to an exemplary embodiment, the objective lens is an objectivelens having a working distance which may be changed in order to change adistance between the focus region and the objective lens.

According to an exemplary embodiment, the change of the working distanceis also based upon the position signal. According to an alternativeembodiment, the microscopy optics can comprise an auto-focus system inorder to measure a distance between the objective lens and the observedobject and to adjust the working distance such that the focus regioncoincides with the interesting region of the observed object.

According to a further exemplary embodiment, the microscopy systemcomprises a mouth switch being firmly connected with the objective lens.The mouth switch may be actuated by a mouth of the user while lookinginto oculars of the microscopy optics. By this, the user can releasebrakes which block the relative displacement of the hinges of the firstgroup of hinges when the mouth switch is not actuated and is able toapply a necessary force for the displacing of these hinges also via themouth switch onto the objective lens and thus onto the stand.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, exemplary embodiments of the present invention areexplained in further details with reference to the figures, wherein

FIG. 1 is an illustrative perspective schematic view of a microscopysystem according to an embodiment of the invention;

FIG. 2 is a schematic illustration of the microscopy optics of themicroscopy system shown in FIG. 1 in two different positions; and

FIG. 3 is a schematic illustration of a controller for controlling themicroscopy system shown in FIG. 1.

DETAILED DESCRIPTION

In the exemplary embodiments described below, components that aresimilar in function and structure are designated as far as possible bysimilar reference numerals. Therefore, to understand the features of theindividual components of a specific embodiment, the descriptions ofother embodiments and of the summary of the invention should be referredto.

FIG. 1 shows a schematic perspective view of a microscopy system 1comprising a microscopy optics 3, mounted on and carried by a stand 5.The stand 5 comprises, as a base stand member, a pedestal 9 havingwheels 7. The base stand member 9 supports a further stand member 13 viaa pivot hinge 11 being ratable about a vertically extending pivot axis15. A further stand member 17 is displaceably supported on the standmember 13 via a hinge 19 having a horizontal pivot axis 21. Again, atstand member 17, a further stand member 23 is displaceably supported viaa hinge 25 about a horizontal pivot axis 27. Again, at stand member 23,a further stand member 29 is displaceable supported via a hinge 31around a horizontal pivot axis 33. Again, the stand member 29 supports astand member 35 being displaceable via a hinge 37 around a pivot axis39. Again, at the stand member 35, a further stand member 41 is, via ahinge 43, displaceable hinged around a pivot axis 45, and, finally, achassis 47 of the microscope is displaceably hinged via a hinge 49around a pivot axis 51 to the stand member 41. By this, the microscope 3can be displaced within a useful working volume and can be oriented bydisplacing the stand members around the pivot axes.

Two counter-balances 18 of the stand 5 are configured to balance themicroscope 3 with respect to the pivot axes 21 and 27, and the user onlyneeds to overcome a remaining friction force in order to displace thestand around these axes. Also for displacing the stand around thevertically oriented pivot axis 15, the user only needs to overcome aremaining friction force.

In FIG. 2, the microscope 3 is shown in two different positions, namelyin a position I on the right hand side and in a position II on a lefthand side, whereby only stand member 41 of the stand 5 is shown.

The microscope 3 comprises a microscopy optics having an objective lens53 which comprises two lens groups 54 and 55 which are displaceable viaan actuator 59 along an optical axis 57 in order to adjust a workingdistance A between the lens group 54 and an object plane 61 such thatthe object plane coincides with a part of a surface of an object 63 tobe observed. A focus region 65 which comprises a part of the object 63is imaged by the objective lens 53 and the image is supplied to a pairof zoom systems 67 which further supply the image to a pair of oculars69. The user of the microscopy system 1 looks with both of his eyes intothe oculars in order to perceive an enlarged stereoscopic representationor image of the object 63 being disposed in the focus region 65.

Let it be assumed that the microscopy optics is to be moved fromposition I into position II. The corresponding movement or displacementof the microscopy optics may be understood as a translationaldisplacement of a location 71, which is disposed on the optical axis 57at a working distance A from the object plane 61, by a distance X and afurther rotational displacement of the microscopy optics by an angle αabout the location 71. Further the working distance A is changed from avalue A₁ in position I to a value A₂ in position II. Herein, thetranslational displacement (X), the rotational displacement (α) and thechange of the working distance (A) are performed such that the focusregion 65 remains at a substantially constant position, namely at a samelocation at the object 63 to be observed such that the substantiallysame location of the object 63 can be observed in the positions I and IIfrom different points of view or under different viewing angles.

In FIG. 2, the translational displacement X is oriented parallel to thex-direction of the coordinate system for ease of illustration. This isnot limiting however, and the translational displacement X may beoriented in any direction, accordingly.

The arrangement of the microscope 3 in position I and the subsequentdisplacement into position II will be illustrated with reference to FIG.3 below.

The hinges 11, 19 and 25 each comprise a brake 85 preventing anaccidental displacement of the stand members around the respective axesof the hinges 11, 19 and 25. The brakes 85 are controlled by acontroller 87 and are released when the user activates a switch 89. Theswitch 89 may, for example, be embodied as a mouth switch which ismounted on the microscope chassis 47 in a manner that it can be actuatedby the user with his mouth while looking into the oculars 69 with hiseyes. An example of a mouth switch is known in the art from U.S. Pat.No. 3,887,267, and the full disclosure of this document is incorporatedherein by reference. An actuation of the mouth switch 89 is detected bythe controller 87, whereupon the controller 87 controls the brakes 85,such that they release the blocking in the hinges, and the stand memberswhich are connected to each other by the hinges can be displaced aboutthe respective axes with respect to each other. Then, the user can applya force onto the stand 5 or the microscope chassis 47, in order todisplace the microscope 3 near the object 63. The hinges 31, 43 and 49do not permit free displaceability of the stand members being connectedwith each other by these hinges. These hinges each have an actuator 91,which is controlled by the controller 87 according to the inputs of theuser via a joystick 93 in order to change the orientation of the opticalaxis 57. By this, the user can move the microscope 3, with respect tolocation and orientation, into the position I shown in FIG. 2 andobserve the desired region of the object 63.

After this, the user actuates a switch 94 in order to switch thecontroller 87 into an automatic control mode.

In this automatic control mode, the user can actuate switch 89, in orderto release the brakes 85 and displace the stand members being connectedby the hinges 11, 19 and 25 with respect to each other. Further, thecontroller 87 obtains measuring values of angle sensors 97, which arecomprised in the hinges 11, 19 and 25 respectively, in order to detectthe positions of the stand members which are connected with each otherby the hinges 11, 19 and 25 relative to each other.

Then, the controller 87 controls the actuators 91 of the hinges 31, 43and 49 in dependence of the detected changes in positions with an goalthat a point P of intersection of the object plane 61 and the opticalaxis 57 remains as far as possible at a same position. In order toachieve this as far as possible, also the actuator 59 is controlled bythe controller 87 in order to change the working distance A of theobjective lens 3.

Thus, after actuating the switch 89, the user can displace themicroscope 3 by applying a force onto microscope 3 or the stand 5,wherein the hinges 31, 43 and 49 being provided with actuators 91 can becontrolled automatically, in order to maintain the focus region 65 at asubstantially same position of the object 63.

The automatic control mode of the controller 87 can again be switchedoff by actuating the switch 94 or by actuating the joystick 93.

According to another exemplary embodiment, all or some of the hinges 31,43 and 49 being provided with actuators 91 each comprise a brake, whichinhibits an accidental displacing of the respective hinges. Thisalternative is especially selected when the actuators 91 have a gearwhich is not self-inhibiting. By this, the user can displace the hingesafter releasing the brakes either by actuating the actuators 91 or byapplying a force onto members of the stand 5, by displacing therespective hinges against the force of the actuators 91. For this, theactuators 91 advantageously can have a slipper clutch or similar.

According to another exemplary embodiment, also the hinges 31, 43 and 49may comprise angle sensors in order to detect positions of therespective hinges with respect to each other and to transfer theposition information to the controller 87. By this, a more exactdetermination of the displacement of the microscopy optics (distance Xin FIG. 2) is possible.

According to a further embodiment, the change of the working distancevia actuator 59 is achieved not in dependence of the position data beingdetected by the angle sensors 97, but in dependence of a distancemeasurement result, which is supplied to the controller by a distancesensor 99 (FIG. 3) being integrated into microscope 3, in order to forman auto-focus system. An example of an auto-focus system is illustratedin U.S. Pat. No. 4,516,840, the full disclosure of which is incorporatedherein by reference.

In the above illustrated embodiment, the controller tries as far aspossible to maintain the point of intersection P of object plane 61 andoptical axis 57 at the very location in space where the point P has beenarranged when switching on the automatic control mode. Alternatively,however, there are also other possibilities. For example, coordinates ofthe point P, which the controller tries as far as possible to maintainat a same location, can be supplied to the microscopy system via aninput interface. The input interface may be provided in the form of akeyboard or a mouse or by an interface to a surgery planning andnavigation system, which for example is supplied with physicalexamination data of a preceding NMR exposure or similar of the patientto be operated. Then, the user can, after visualization of these data,select a point therein, which will be transferred to the controller 87via the interface, such that the controller, when switching to theautomatic control mode, tries to maintain the point of intersection ofobject plane 61 and optical axis 57 as near as possible close to thispoint being supplied from external.

Further, a surgery at the brain of a patient is an example where thepoint P which is maintained at substantially a same location doesadvantageously not coincide with the focus region 65. The surgery isperformed through an opening or channel of the cranium, and it isadvantageous to have the point P disposed near the opening of thecranium.

In the embodiment described above, a change of the position of theobjective lens is detected by the position detecting sensors which areprovided in the hinges 11, 19 and 25. Alternatively, the change of theposition may also be determined, for example, by a position detectingsystem being independent of the hinges of the stand. For example, theposition detecting system may detect the position of the objective lensand transfer the coordinates of this position in an appropriate form tothe controller 87. Such a position detection system can also berealized, for example, by applying a mark to the chassis 47 of themicroscope 3, which is observed, for example, by a plurality of cameras.The position can also be determined by a triangulation method.

Incidentally, the brakes can also be released in another way, forexample, by actuating a foot switch or similar being connected to thecontroller. 87 or also by a speech-input means, which senses spokencommands of the user of the microscopy system.

In the above illustrated embodiments, the user perceives the image ofthe focus region generated by the microscope by looking into theoculars. According to other embodiments of the invention, the microscopecomprises a camera detecting a image of the focus region generated bythe objective lens, and a display for displaying the detected image forthe user. The display may comprise a screen, a head mounted display orother types of displays.

In summary, the invention suggests a microscopy system which comprises amicroscopy optics and a stand supporting the microscopy optics. Thestand has a plurality of hinges, of which a first group comprises aposition detecting sensor for sensing a hinge position and a secondgroup comprising an actuator for the change of the hinge position. In anautomatic control mode, the actuators are controlled in dependence ofsignals of the position detecting sensors.

While the invention has been described also with respect to certainspecific embodiments thereof, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, the exemplary embodiments of the invention set forthherein are intended to be illustrative and not limiting in any way.Various changes may be made without departing from the spirit and scopeof the present invention as defined in the following claims.

1. A method of controlling a microscopy system, wherein the microscopysystem comprises: a microscopy optics for imaging the object, themicroscopy optics comprising at least one objective lens having anoptical axis, an object plane and a focus region in which the object tobe imaged is to be disposed, wherein the optical axis intersects withthe object plane within the focus region; and a stand comprising aplurality of stand members and a plurality of hinges, each hingeconnecting a pair of stand members such that the stand members connectedby the respective hinge may be displaced relative to each other, theplurality of stand members comprising a base stand member and anobjective lens supporting stand member supporting the at least oneobjective lens; wherein the method comprises: allowing a displacement ofat least one stand member of at least one of a first pair of standmembers, a second pair of stand members and a third pair of standmembers, the stand members of the pairs of stand members connected toeach other by a first hinge, a second hinge and a third hinge,respectively, about a pivot axis of the respective hinge by allowing theat least one stand member, which is connected to the other stand memberby the respective hinge, to be freely and manually displaceable relativeto the other stand member about the pivot axis of that hinge whileblocking a relative displacement of at least one pair of stand membersconnected to each other by at least one fourth hinge, which is differentfrom the first hinge, the second hinge and the third hinge,respectively; then detecting, upon the displacement of the at least onestand member of the at least one of a first pair of stand members, asecond pair of stand members and a third pair of stand members, a changeof a position of the at least one objective lens due to the displacementof the at least one stand member; and then operating an actuator fordisplacing relative to each other the at least one pair of stand membersconnected to each other by the fourth hinge about a pivot axis of thefourth hinge based upon the detected change of the position of the atleast one objective lens.
 2. The method according to claim 1, whereinthe detecting of the change of the position of the at least oneobjective lens comprises detecting a relative position of the at leastone of a first pair of stand members, a second pair of stand members anda third pair of stand members.
 3. The method according to claim 2,further comprising: changing a working distance between the at least oneobjective lens and the object plane based upon the detected change ofthe position of the at least one objective lens.
 4. The method accordingto claim 1, further comprising: blocking a relative displacement of theat least one of a first pair of stand members, a second pair of standmembers, and a third pair of stand members.
 5. The method according toclaim 4, wherein the blocking is performed in dependence of a first userinput.
 6. The method according to claim 1, further comprising:displacing relative to each other the at least one pair of stand membersconnected to each other by the at least one fourth hinge in dependenceof a second user input.
 7. A method of controlling a microscopy systemcomprising at least one objective lens, the method comprising the stepsof: allowing a displacement of at least one stand member of at least oneof a first pair of stand members, a second pair of stand members and athird pair of stand members, the stand members of the pairs of standmembers connected to each other by a first hinge, a second hinge and athird hinge, respectively, about a pivot axis of the respective hinge byallowing the at least one stand member, which is connected to the otherstand member by the respective hinge, to be freely and manuallydisplaceable relative to the other stand member about the pivot axis ofthat hinge while blocking a relative displacement of at least one pairof stand members connected to each other by at least one fourth hingewhich is different from the first hinge, the second hinge and the thirdhinge, respectively; then detecting, upon the displacement of the atleast one stand member of the at least one of a first pair of standmembers, a second pair of stand members and a third pair of standmembers, a change of a position of the at least one objective lens dueto the displacement of the at least one stand member; and then operatingan actuator for displacing relative to each other the at least one pairof stand members connected to each other by the fourth hinge about thepivot axis of that hinge based upon the detected change of the positionof the at least one objective lens.
 8. The method according to claim 7,wherein the detecting of the change of the position of the at least oneobjective lens further comprises: detecting a relative position of theat least one of a first pair of stand members, a second pair of standmembers and a third pair of stand members.
 9. The method according toclaim 8, further comprising: changing a working distance between the atleast one objective lens and an object plane based upon the detectedchange of the position of the at least one objective lens.
 10. Themethod according to claim 7, further comprising: blocking a relativedisplacement of the at least one of a first pair of stand members, asecond pair of stand members and a third pair of stand members.
 11. Themethod according to claim 10, wherein the blocking is performed based ona user input.
 12. The method according to claim 7, further comprising:displacing, relative to each other, the at least one pair of standmembers connected to each other by the at least one fourth hinge basedupon a user input.